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Updated: Aug 6, 2026
08:51
Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling
Published on: June 25, 2015
Pathogenicity island integrase cross-talk: a potential new tool for virulence modulation
Janet M Manson1, Michael S Gilmore
1Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
Molecular Microbiology
|August 2, 2006
Summary
Pathogenicity islands (PAIs) in Escherichia coli 536 are unstable due to a P4-type integrase. This integrase mediates site-specific recombination, enabling PAI excision and integration, impacting genome evolution and horizontal gene transfer.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Pathogenicity islands (PAIs) are mobile genetic elements contributing to bacterial virulence.
- Instability and excision of PAIs have been previously observed in Escherichia coli 536.
Discussion:
- A P4-type integrase encoded within PAI II(536) mediates site-specific recombination for PAI instability.
- This integrase facilitates the excision and integration of PAI II(536) and PAI V(536).
- The integrase exhibits cross-PAI activity, suggesting a significant role in genome evolution and horizontal gene transfer.
Key Insights:
- The att sites of PAI II(536) and PAI V(536) share sequence similarity with other PAIs and bacterial tRNA genes.
- The cross-PAI activity of Int(PAI II) highlights its importance in the spread of pathogenicity elements, potentially across species.
- PAI deletion can induce phase variation-like phenomena, affecting bacterial traits like adhesin expression.
Outlook:
- Differential regulation of integrase activity could fine-tune bacterial infection processes.
- Understanding PAI dynamics is crucial for comprehending bacterial adaptation and virulence.
- This research provides insights into the mechanisms driving the evolution and dissemination of bacterial virulence factors.
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